Gate valves are widely used to control the rate of flow of fluids through conduits, and especially to provide a shut-off capability. They vary widely in complexity, materials of construction, and cost. All too often reliability must be purchased by the use of more expensive materials of construction which frequently require costly machining processes.
It is an object of this invention to provide a gate valve which can principally be formed of injection molded parts made from organic plastic material. The major portion of the body, including its valve seats, are formed of a single molded piece. This includes a cap which can readily and reliably be joined to the body by solvent or heat welding. The cap and all other elements except for a single actuator rod, are molded parts. There results an economical and strong gate valve whose parts can expediently be assembled. The assembled valve is reliable and can provide features of reassurance to its users.